Curiosities: Why do cactuses have spines?

Mother Nature provided cactuses with spines to protect them against animals that want to eat them and other predators.

Cactuses have to battle not only the lack of water, but temperature too. Remember the drought conditions in the arid regions where these plants grow in. A lot of water “escapes” from these plants into the atmosphere as water vapor during a process called transpiration. Then, here we have another important role for the spines: They also help to reduce transpiration by deflecting sunlight. The spines are actually modified leaves that have lost their liquid substances because of direct sunlight, or rather, evaporation.